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From: Qian Cai <cai@lca.pw>
To: saeedm@mellanox.com
Cc: leon@kernel.org, davem@davemloft.net, moshe@mellanox.com,
	ferasda@mellanox.com, eranbe@mellanox.com,
	netdev@vger.kernel.org, linux-rdma@vger.kernel.org,
	linux-kernel@vger.kernel.org, Qian Cai <cai@lca.pw>
Subject: [PATCH] net/mlx5: fix a -Wstringop-truncation warning
Date: Fri, 23 Aug 2019 15:56:23 -0400	[thread overview]
Message-ID: <1566590183-9898-1-git-send-email-cai@lca.pw> (raw)

In file included from ./arch/powerpc/include/asm/paca.h:15,
                 from ./arch/powerpc/include/asm/current.h:13,
                 from ./include/linux/thread_info.h:21,
                 from ./include/asm-generic/preempt.h:5,
                 from ./arch/powerpc/include/generated/asm/preempt.h:1,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/wait.h:9,
                 from ./include/linux/completion.h:12,
                 from ./include/linux/mlx5/driver.h:37,
                 from
drivers/net/ethernet/mellanox/mlx5/core/lib/eq.h:6,
                 from
drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.c:33:
In function 'strncpy',
    inlined from 'mlx5_fw_tracer_save_trace' at
drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.c:549:2,
    inlined from 'mlx5_tracer_print_trace' at
drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.c:574:2:
./include/linux/string.h:305:9: warning: '__builtin_strncpy' output may
be truncated copying 256 bytes from a string of length 511
[-Wstringop-truncation]
  return __builtin_strncpy(p, q, size);
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fix it by using the new strscpy_pad() since the commit 458a3bf82df4
("lib/string: Add strscpy_pad() function") which will always
NUL-terminate the string, and avoid possibly leak data through the ring
buffer where non-admin account might enable these events through perf.

Fixes: fd1483fe1f9f ("net/mlx5: Add support for FW reporter dump")
Signed-off-by: Qian Cai <cai@lca.pw>
---
 drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.c b/drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.c
index 8a4930c8bf62..2011eaf15cc5 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.c
@@ -546,7 +546,7 @@ static void mlx5_fw_tracer_save_trace(struct mlx5_fw_tracer *tracer,
 	trace_data->timestamp = timestamp;
 	trace_data->lost = lost;
 	trace_data->event_id = event_id;
-	strncpy(trace_data->msg, msg, TRACE_STR_MSG);
+	strscpy_pad(trace_data->msg, msg, TRACE_STR_MSG);
 
 	tracer->st_arr.saved_traces_index =
 		(tracer->st_arr.saved_traces_index + 1) & (SAVED_TRACES_NUM - 1);
-- 
1.8.3.1


             reply	other threads:[~2019-08-23 19:56 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-23 19:56 Qian Cai [this message]
2019-08-23 22:18 ` [PATCH] net/mlx5: fix a -Wstringop-truncation warning David Miller
2019-08-26 20:18   ` Saeed Mahameed
2019-08-26 21:11 ` Saeed Mahameed
2019-08-27 20:12   ` Qian Cai
2019-08-27 21:46     ` Saeed Mahameed
2019-08-27 21:51 ` Saeed Mahameed

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